Here are some thoughts on elevator door buttons and design inspirations I got from the observation.

Common issues:

1. Language – there’re thousands of words in different languages to communicate the “open” and “close” functions. English is [open/close], Chinese is [開／關] or [开／关] (simplified Chinese), Japanese is [開／閉],…etc.
2. Icon – to solve the language problems stated above, it’d be better to use icons that is universally understandable regardless of the language barrier.
3. Button location – Some elevators has the open/close buttons located at the top of the button panel. While one person is pressing the [open] button to keep the door open, other people sometimes has to squeeze under his/her armpit to press the floor buttons. That’s quite inconvenient and could be embarrassing.
4. Mutual exclusive states – “open” and “close” are two mutually exclusive states of one object: the door. Logically, you only need one control to operate the door. Think about a light switch: one switch is connected to one lightbulb to turn it ON or OFF. However, perhaps when the engineer first designed the elevator, the two functions was identified as two separate tasks where each has to be implemented and engineered separately. Thus, the two buttons are mapped to control the two functions.
5. Accessibility – what if the user is colour blind or unable to see? What if the light goes out and you can only rely on touch?

A good solution

1. Language independence.
2. Every control should have at least two or more ways to communicate its function.
• Colour (green is open / black is close)
• Icon (outside pointing arrows is open / inside pointing arrows is close)
• Physical dimension (wider button is open / narrower button is close)

Real world example